PB1794: NATURAL FLAVONOIDS INHIBIT MYELOID NEOPLASM PROLIFERATION BY REGULATING PIM2 KINASE ACTIVITY
Authors: Hao Wang, Zhaoyun Liu, Rong Fu
Journal: HemaSphere (2023)

Topic: 3. Acute myeloid leukemia - Biology & Translational Research Background: Natural compounds account for a large part of today’s pharmaceutical preparations, especially in the field of cancer treatment. Traditional Chinese medicine (TCM) and its active components have been used for a long time in the treatment of cancer with multi-target pharmacological effects and minor side effects. In this context, we screened two flavonoids Kaempferol and Quercetin Dihydrate from natural flavonoids compounds,which have previously been reported to have antitumor effects on a variety of cancers.But the mechanism of treatment in myeloid neoplasms remains unclear. Aims: To investigate whether Kaempferol and Quercetin Dihydrate can inhibit myeloid neoplasms and the related mechanisms. Methods: Three myeloid neoplasm lines were selected for culture, including leukemia cell lines K562 and ThP1, and myelodysplastic syndrome cell line SKM1. Cell viability was measured by using the tetrazolium salt-based CCK-8 assay (Bimake, Inc.). Apoptosis of all cell lines was measured by flow cytometry 48 h after Kaempferol and Quercetin Dihydrate was added. Western blot was used to evaluate the content of cleaved caspase-3, Bcl-2, and Bax in cell extracts after using Kaempferol and Quercetin Dihydrate. Western blotting was also used to investigate whether Kaempferol and Quercetin Dihydrate inhibit PIM2 kinase and regulate NF-KB in myeloid neoplasms cells After 48 h of drug treatment.Further confirmed by lentivirus transfection, PIM-2 was knocked down by siRNA, PIM2 and NF-KB expressions were measured. Results: we demonstrate that Kaempferol and Quercetin Dihydrate inhibited cell proliferation. Kaempferol and Quercetin Dihydrate inhibit myeloid neoplasms proliferation by down-regulating Bcl2 expression and up-regulating cleaved Caspase-3 and Bax protein expression, inducing tumor cell apoptosis. Two compounds were identified to regulate myeloid neoplasmss by inhibiting PIM2 kinase. PIM2 kinase expression decreased in all cell lines after addition of Kaempferol or Quercetin Dihydrate. The addition of compound Kaempferol has little effect on PIM1 kinase expression, but PIM3 kinase expression may be increased. PIM1, PIM2, and PIM3 kinase expression is decreased due to Quercetin Dihydrate. These results suggest that Kaempferol and Quercetin Dihydrate may be good PIM2 inhibitors. Summary/Conclusion: Kaempferol and Quercetin Dihydrate inhibit proliferation and induce apoptosis of myeloid neoplasms cells. PIM2 is an important target for the development and prognosis of acute myeloid leukemia and MDS. Kaempferol and Quercetin Dihydrate inhibit PIM2 kinase in myeloid neoplasms cells and subsequently participate in NF-κB expression, proliferation and regulation of myeloid neoplasms. These results suggest that Kaempferol and Quercetin Dihydrate may be good PIM2 inhibitors. This study raises the general awareness of the anticancer effects of natural flavonoids compounds, thus promoting the development of natural anticancer drugs with less toxic and side effects, and providing new ideas for the treatment of myeloid neoplasms.Figure A.Kaempferol and quercetin dihydrate inhibit proliferation of myeloid tumor cells.B.Kaempferol and quercetin dihydrate induce myeloid neoplasms apoptosis.C.PIM kinase inhibitors SMI-16A and AZD-1208 for each cell line.D.Effect of kaempferol and quercetin dihydrate on the expression of Bcl2, cleaved caspase-3, and Bax proteins.E.Kaempferol and quercetin dihydrate inhibit myeloid tumor cell proliferation by inhibiting PIM2/NF-κB cell pathway. F.Kaempferol and quercetin dihydrate inhibit the PIM2/NF-κB cell pathway. Keywords: Apoptosis, Inhibitor, NF- B, Leukemia